Joe Biden has launched one of his most scathing attacks yet on Donald Trump’s record of racism, suggesting that the former US president would have acted differently to the January 6 2021 insurrection if was led by Black people.

The remarks, at a dinner hosted by a civil rights organisation in a critical swing state, pointed to an intensifying battle between Biden and Trump for African American voters ahead of November’s presidential election.

“Let me ask you,” Biden said during an address to an NAACP (National Association for the Advancement of Colored People) dinner in Detroit. “What do you think he would have done on January 6 if Black Americans had stormed the Capitol?”

There was a collective gasp and murmur in the cavernous convention centre, where an estimated 5,000 guests had gathered. The president insisted: “No, I’m serious. What do you think? I can only imagine.”